From 2caee0fac86165730b676727390dc74852f9663d Mon Sep 17 00:00:00 2001 From: Noel Grandin Date: Fri, 17 Aug 2018 12:18:02 +0200 Subject: new loplugin intvsfloat This was a good idea from mike kaganski as a consequence of https://gerrit.libreoffice.org/55359 Unfortunately, clang/llvm is not yet up to the job of doing floating point evaluation, I get tons of crashes all over the evaluate infrastruction inside clang, so this will need to wait until clang's code matures. So park it in store for now Change-Id: I5ba4de8323e462b4fd4db301e4d116a81fd56ed3 Reviewed-on: https://gerrit.libreoffice.org/59254 Tested-by: Jenkins Reviewed-by: Noel Grandin --- compilerplugins/clang/store/intvsfloat.cxx | 109 +++++++++++++++++++++++++++++ compilerplugins/clang/test/intvsfloat.cxx | 69 ++++++++++++++++++ 2 files changed, 178 insertions(+) create mode 100644 compilerplugins/clang/store/intvsfloat.cxx create mode 100644 compilerplugins/clang/test/intvsfloat.cxx diff --git a/compilerplugins/clang/store/intvsfloat.cxx b/compilerplugins/clang/store/intvsfloat.cxx new file mode 100644 index 000000000000..3189d982d9c0 --- /dev/null +++ b/compilerplugins/clang/store/intvsfloat.cxx @@ -0,0 +1,109 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +#include "plugin.hxx" +#include "check.hxx" +#include "compat.hxx" +#include + +/** + +TODO multiplying/otherop on a combination of a float and int, and then truncating to int. like this: + float getRotation() {} + int moRotation; + moRotation = -F_PI180 * 90 * getRotation(); + +*/ +namespace +{ +class IntVsFloat : public loplugin::FilteringPlugin +{ +public: + explicit IntVsFloat(loplugin::InstantiationData const& data) + : loplugin::FilteringPlugin(data) + { + } + + void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); } + + bool VisitVarDecl(VarDecl const*); + bool VisitBinEQ(BinaryOperator const*); + +private: + llvm::Optional getExprValue(Expr const* expr); +}; + +bool IntVsFloat::VisitVarDecl(VarDecl const* varDecl) +{ + if (ignoreLocation(varDecl->getLocation())) + return true; + auto init = varDecl->getInit(); + if (!init) + return true; + init = init->IgnoreImpCasts(); + if (varDecl->getType()->isFloatingType()) + return true; + // init->dump(); + llvm::Optional d = getExprValue(init); + if (!d) + return true; + if (static_cast(*d) == *d) + return true; + report(DiagnosticsEngine::Warning, "assigning constant float value to int truncates data", + compat::getBeginLoc(init)) + << init->getSourceRange(); + + return true; +} + +bool IntVsFloat::VisitBinEQ(BinaryOperator const* op) +{ + if (ignoreLocation(compat::getBeginLoc(op))) + return true; + auto lhs = op->getLHS()->IgnoreImpCasts(); + auto rhs = op->getRHS()->IgnoreImpCasts(); + if (!lhs->getType()->isFloatingType()) + std::swap(lhs, rhs); + if (!lhs->getType()->isFloatingType()) + return true; + if (rhs->getType()->isFloatingType()) + return true; + llvm::Optional d = getExprValue(lhs); + if (!d) + return true; + if (static_cast(*d) == *d) + return true; + report(DiagnosticsEngine::Warning, "comparing integer to float constant, can never be true", + compat::getBeginLoc(op)) + << op->getSourceRange(); + return true; +} + +llvm::Optional IntVsFloat::getExprValue(Expr const* expr) +{ + // Of the available clang Evaluate* APIs, this is the __only__ one that produces useful output + // (as of 17 Aug 2018 checkout of clang, ie. towards clang 7) + + Expr::EvalResult evalResult; + if (!expr->EvaluateAsRValue(evalResult, compiler.getASTContext())) + return llvm::Optional(); + if (!evalResult.Val.isFloat()) + return llvm::Optional(); + llvm::APFloat floatResult = evalResult.Val.getFloat(); + bool losesInfo; + floatResult.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &losesInfo); + + double d = floatResult.convertToDouble(); + return d; +} + +loplugin::Plugin::Registration X("intvsfloat"); +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ diff --git a/compilerplugins/clang/test/intvsfloat.cxx b/compilerplugins/clang/test/intvsfloat.cxx new file mode 100644 index 000000000000..7c753c3667ab --- /dev/null +++ b/compilerplugins/clang/test/intvsfloat.cxx @@ -0,0 +1,69 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + */ + +static const float PI = 3.4; +struct Class1 +{ + float getFloat() const { return 1.5; } + int getInt() const { return 1; } + static constexpr float PI = 3.4; + static constexpr float E() { return 3.4; } +}; + +void func1(Class1 const& class1) +{ + if (1 + == PI) // expected-error {{comparing integer to float constant, can never be true [loplugin:intvsfloat]}} + return; + if (1 + == class1 + .PI) // expected-error {{comparing integer to float constant, can never be true [loplugin:intvsfloat]}} + return; + if (true + == class1 + .PI) // expected-error {{comparing integer to float constant, can never be true [loplugin:intvsfloat]}} + return; + if (1 == class1.getInt()) // no warning expected + return; + if (1 + == class1 + .E()) // expected-error {{comparing integer to float constant, can never be true [loplugin:intvsfloat]}} + return; + if (true + == class1 + .E()) // expected-error {{comparing integer to float constant, can never be true [loplugin:intvsfloat]}} + return; + if (1 == class1.getFloat()) // no warning expected + return; +} + +void func2(Class1 const& class1) +{ + int i0 + = PI; // expected-error {{assigning constant float value to int truncates data [loplugin:intvsfloat]}} + (void)i0; + int i1 + = class1 + .PI; // expected-error {{assigning constant float value to int truncates data [loplugin:intvsfloat]}} + (void)i1; + int i2 + = class1 + .E(); // expected-error {{assigning constant float value to int truncates data [loplugin:intvsfloat]}} + (void)i2; + int i3 = class1.getFloat(); // no warning expected + (void)i3; + int i4 = class1.getInt(); // no warning expected + (void)i4; + bool b1 + = class1 + .E(); // expected-error {{assigning constant float value to int truncates data [loplugin:intvsfloat]}} + (void)b1; +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */ -- cgit